Designing Gestural Interfaces

Chapter 4. Patterns for Free-Form Interactive Gestures

"Sense, sure, you have, Else you could not have motion."

—William Shakespeare, Hamlet, Act III, Scene IV

The following are patterns for gestures that are typically done in space, not via a touchscreen or other interactive surface. Of course, these patterns don't have to be mutually exclusive; free-form and touchscreen patterns can exist on the same device. For instance, a touchscreen kiosk may use Proximity Activates/Deactivates as a way to turn the kiosk on and off.

PROXIMITY ACTIVATES/DEACTIVATES

WHAT

This pattern is for performing the simplest of all gestures, requiring only the presence of a person without any direct body contact (except perhaps to a pressure sensor). When a body is detected, an action triggers.

USE WHEN

Use Proximity Activates/Deactivates to trigger simple on/off settings, such as lighting, display changes, sound, and other environmental controls.

WHY

Environmental and cost-saving concerns have driven the adoption of this pattern. For instance, if lights come on only when a person is in the room, it saves energy (and money).

HOW

The presence of a person can be detected with a variety of means: camera, motion detector, infrared "tripwire," pressure sensor, or microphone.

Of almost all the gestures, this is the one most likely to be triggered accidentally, so care should be taken when calibrating the sensor.

It may be beneficial in certain instances (for privacy or environmental controls) to be able to detect multiple ...